In this work the stratosphere was used as archive of former tropospheric conditions. Laboratory measurements (GC/MS) of CF4, C2F6, and SF6 were carried out on stratospheric air samples obtained by cryosampling between 1983 and 1995. Characteristic relations between height and age of stratospheric air were derived from SF6 values. For heights above 25 km ages of 6-7 years for mid-altitudes and 7-9 years for the arctic winter stratosphere were found. By correlating this age information with mixing ratios of the perfluorated carbons increase rates of 1 ppt/y for CF4 and 0.09 ppt/y for C2F6 are determined for the period 1980-1995, which translates into annual injection rates of 14000 t/y and 2000 t/y respectively. Assuming aluminium production as the only major source average emissions per ton of primary aluminium are thus calculated to be 0.75 kg for CF4 and 0.11 kg of C2F6 in 1990. The mass ratio of CF4/C2F6 in the atmosphere is observed to have decreased from well above 30 in 1980 to below 20 in 1995.